Bacterial colonization of the eyelids is normal, but there are a number of conditions where this bacterial colonization or bacterial over-colonization of the eyelids poses a problem. One of the most serious complications of eye surgery is a secondary infection of the eyeball called endophthalmitis. It has been shown that the bacteria that cause endophthalmitis come from the eyelid margin (Speaker M G, Milch F A, Shah M K, et al. Role of external bacterial flora in the pathogenesis of acute postoperative endophthalmitis. Ophthalmology (United States), May 1991, 98(5) p 639-49). Another condition of clinical significance is inflammation of the eyelids that frequently results in symptoms of eye irritation called blepharitis. In a study involving 332 patients with blepharitis and 160 normal controls, it has been shown that blepharitis patients have greater quantities of bacteria on their eyelids compared to normal controls. This finding applied to patients with both anterior and posterior blepharitis (Groden L R, Murphy B, Rodnite J, et al. Lid flora in blepharitis. Cornea (United States), January 1991, 10(1) p 50-3). Bacterial overgrowth has been hypothesized to contribute to the symptoms of blepharitis by the production of bacterial lipases and esterases that hydrolyze the wax and sterol esters in meibum, creating free fatty acids that are irritating to ocular tissue and may effect tear film stability (Ta C N, Shine W E, McCulley J P, et al. Effects of minocycline on the ocular flora of patients with acne rosacea or seborrheic blepharitis. Cornea (United States), August 2003, 22(6) p 545-8). In addition these fatty acids may promote eyelid and ocular surface inflammation (Shine W E, McCulley J P, Pandya A G Minocycline effect on meibomian gland lipids in meibomianitis patients. Exp Eye Res (England), April 2003, 76(4) p 417-20).
Moreover, a condition known as dry eye causes chronic eye irritation resulting from decreased tear production or increased evaporation that results in a loss of water from the tear film and an increase in tear film osmolarity. This increase in tear film osmolarity results in an osmotic dehydration of the surface associated with a decrease in the density of conjunctival goblet cells. Recently it has been shown that dry eye patients have increased bacterial colonization of their eyelids, and that the bacteria found in these patients decrease the proliferation of conjunctival goblet cells in tissue culture ((Graham et al Analysis of Bacterial Flora in Dry Eye, Ocular Surface, 3(1):S68, 2005).
Punctal plugs are a frequently used treatment for dry eye. They provide symptomatic relief for patients with dry eye, reduce elevated tear film osmolarity in the disease and reduce ocular surface staining. A problem with punctal plugs is that they are frequently colonized by pathogenic noncomensals, including Pseudomonas aeruginosa and Staphylococcus aureus, that may cause symptoms and increase the risk of eye infections (Soukiasian S H Microbiology of Explanted Punctal Plugs, ARVO Annual Meeting, Program#/Poster#4981/B305, Apr. 29, 2004).
Eyelid or lid hygiene has been recommended for all of these conditions or circumstances by eye doctors. The most common recommendation is to dilute baby shampoo 1:10 with water, and to use the dilution to moisten a pad or cotton tip swab to scrub the lid margin. In addition there are multiple products on the market that package gentle soap with pads or cotton tips or saturate pads with such soap, to facilitate performing eyelid hygiene or cleansing. None of these products is sufficiently anti-bacterial to kill eyelid bacteria within clinically relevant exposure times.
Accordingly, a need exists for an effective antibacterial preparation that can be used in or around the eye and does not cause clinically significant conditions to the site of application.